Retaining means for circuit breaker handle

ABSTRACT

A multipole molded case circuit breaker is provided with a manual operating handle that is snap-fitted to the handle extension so that when the circuit breaker cover is removed the handle will be retained by the extension.

United States Patent Strobe] et a].

[ 1 Nov. 11, 1975 [54] RETAINING MEANS FOR CIRCUIT 2,840,657 6/1958 Roeser 200/303 x B E KE HANDLE 2.863.969 12/1958 Edmunds 1. 200/303 X 3,121,778 2/1964 Sander et a1 200/331 [75] In ntors: Al rt Strobel, Cherry Hill, N 3.201.557 8/1965 Poulton, Jr. 200/331 Anthony B. Michetti, Warminster, 3,412,225 11/1968 Rogers et a1 200/303 X P21. 3,444,345 5/1969 Mackiewicz 200/303 X 73 Assi nee: I-T-E Im erial Cor o t' S I 1 g p m on prmg Primur Examiner-Robert K. Schaefer House, Pa. Assistant ExaminerWilliam J. Smith F1led3 y 13, 1974 Attorney, Agent, or Firm-Ostrolenk, Faber, Gerb & [21] Appl. No; 469,120 Sofie" [52] us. c1. 200/331; 200/153 G; 200/339 [571 ABSTRACT C132 r A multipole molded case ircuit breaker is provided [58] Field of Search 200/330, 331, 332, 339, with a manual Operating handle that is snapfltted to 200/153 R, 153 G, 335, 337', 74/5 the handle extension so that when the circuit breaker cover is removed the handle will be retained by the [56] References Cited extension UNITED STATES PATENTS 8 Cl D 2,580,905 1/1952 Foster 200/331 rawmg gums EZ W Z US. Patent Nov. 11,1975 Sheet10f3 3,919,514

US. Patent Nov. 11, 1975 Sheet 2 of3 3,919,514

U.S. Patent Nov. 11, 1975 Sheet 3 01-3 3,919,514

RETAINING MEANS FOR CIRCUIT BREAKER HANDLE This invention relates generally to circuit breakers and relates more particularly to securement of a molded insulating handle to a handle extension.

A multipole molded case circuit breaker is provided with a single molded insulatingoperating handle having a manually engageable portion projecting through an aperture in the cover of the circuit breaker housing.

Within the housing the handle is in operative driving engagement with a handle extension that is connected to the main springs of the circuit breaker contact operating mechanism so than movement of the handle serves to reposition the line of action of the main springs for openin g and closing of the circuit breaker.

It often happens tha t circuit breakers of this type are provided with interchangeable fault responsive automatic trip units that are accessible for rernoval and replacement by opening the cover at the front ,of the circuit breaker housing. These covers ,rnus t be removable in the field. Forthe most part, itis intended that a multipole molded case circuit breaker be mounted withits front cover in a vertical plane. When this cover is removed, unless the handle is fastened to the handle extension, the handle will separate from the handle. extension and can be lost or damaged. Thus, the prior art positively fastensthe handleto the extension by providing the handle witha metal insert that was staked o nriveted to the handle extensiom-or by utilizing screws that were entered through clearance apertures in the sides of the handle and received by threaded apertures in-the handle extensions. These: securing methods. have proven to be unnecessarily costly. Further,.t here is ,al-

ways the danger that the" screws will become loose, thereby rubbing against the housing to add friction and make the breaker more difficult to operate. Still further, loose screws may cause dielectric breakdown between the breaker line terminals and the open contact operating mechanism along a path on the inside walls of the housing and extending through the head of the loose handle screw.

Thus, in accordance with the instant invention, the

molded handle is snap fitted to the handle extension so as to be securely retained thereon when the circuit breaker cover is open. With the cover secured in place, the cover serves to block separation of the handle from the handle extension. The snap fit between the handle and handle extension is achieved by providing outward tion is to provide novel means for securing a circuit breaker handle to the handle extension connected to the contact operating mechanism.

Another object is to provide a securing means of this type which is economical and is superior from an electrical standpoint.

Still another object is to provide a securing means of this type in which the handle is snap fitted to the handle extension.

I These objects 'a's 'well as other objects of this invention-will become readily apparent after reading the fol- "l'ow'in'g description of the accompanying drawings in which: i

1 FIG. 1 is a plan view ofja multipolemolded case circuit breaker having an interchangeable' trip unit] FIG. 2 is a cross-section taken' thr ough line 22 of FIG. 1, looking in the direction of arrows 2 2.

i I FIG. 3 is a side elevation of the handle extension.

circuit breaker 10 is generally of the type described'in U.S. Pat. No. 3,3 I9,I issued May 9, 19 67, to A. Strobe] et al.'for a CircuitBreake'r Trip I Jnit' Assembly. Briefly, circuit breaker 10 includes a molded housing consisting of base 11 removable main cover 17, and terminal covers 18, 18 at opposite ends of main cover 17. Longitudinal partitions 15, 16 divide base 11 into three compartments 12,13, 14, each housing current carrying element s for asingle pole of circuit breaker 10. With reference to FIG. 2, it is seen that the current path through the center pole consists of line terminal strap 20,,stationaryarcing and main contacts 22, 23,

movable arcing and-main-contacts 24, 25, movable contact arm sections 26, 27, braidsections 28, strap 29 and load terminal strap 1 02. Each of the outer poles includesessentially the same-,eurrent carrying elements asin the center pole., v y,

Circuit breaker 10 also includes removable and replaceable automatic tripping mechanism. and a spring powered toggle-type contact operating mechanism 32. The latter is only in center compartment 13, but is connected to the movable contacts of all three phases by transverse insulating tie bar 33 secured by U-shaped straps 34 to the carriers 35 for the groups of movable contact arms 26, 27. Carrier 35 for the center pole is pivotally mounted at 46 to suitable bearings in frame 47 of operating mechanism 32. Frame 47 includes ears 84 having clearance apertures which receive screws 49 threadably engaged with base inserts 50 for mechanical securement of operating mechanism 32 to base 11.

Center pole carrier 35 is connected at pivot 36 to the lower link of the operating mechanism toggle links 37, 38, with these toggle links being joined at knee 39. Platelike member 40 pivotally mounted to knee 39 is secured to the lower ends of main operating springs 41, 41 having their upper ends secured to the web or base 61 of inverted U-shaped handle extension 60. The lower ends of handle extension arms 62, 62 are seated on pivot bearings 83 mounted to mechanism frame 47.

Molded insulating operating handle 70 is seated on web 61 and includes main section 71 protruding forward of housing 11, 17 through elongated slot 99 in cover 17. Handle 70 also includes arcuate section 72 disposed to the rear of main section 71 and extending in opposite direction therefrom and completely closing off cover slot 99. The forward surface of arcuate section 72 is adjacent to arcuate interior surface 98 of cover 17, so that with cover 17 in the closed position shown in FIG. 2 handle 70 is blocked from moving forward. The driving connection between handle 70 and handle extension 60 is achieved by laterally spaced parallel rods 66, 67 rigidly secured to web 61 and extending forward thereof into elongated recesses 76, 77 of main handle section 71. Outward protrusions 68, 68 formed integrally with arms 62, 62 are disposed within recesses 78, 78 in skirt portions 79, 79 depending from arcuate handle portion 72 along opposite sides thereof. Entry of protrusions 68, 68 into recesses 78, 78 is achieved by a snap-fit made possible by limiting bending of handle 70. Thus, with circuit breaker mounted so that cover 17 thereof is in a vertical plane, when cover 17 is removed, the cooperation of protrusions 68, 68 and recesses 78, 78 will prevent handle 70 from accidentally becoming separated from handle extension 60.

Although there have been described preferred embodiments of this novel invention, many variations and modifications will now be apparent to those skilled in the art. Therefore this invention is to be limited not by the specific disclosure herein but only by the appending claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

l. A circuit breaker including a housing having an openable cover, cooperating contact means disposed within said housing, an operating mechanism disposed within said housing and connected to said contact means for opening and closing the later, a molded insulating handle extending through an opening in said cover, a handle extension disposed within said housing in operative engagement with said operating mechanism, first formation means on said handle and second formation means on said extension, said first and second formation means being snap-fitted to each other for securement of said handle to a portion of said extension disposed within said housing whereby said cover may be opened even while said handle is positively held to said extension.

2. A circuit breaker as set forth in claim 1 in which the first formation means includes spaced recesses and the second formation means includes spaced protrusions that extend into said recesses.

3. A circuit breaker as set forth in claim 2 in which the protrusions are disposed at opposite sides of the extension and extend outboard of said sides.

4. A circuit breaker as set forth in claim 1 in which one of said first and second formation means includes protruding means and the other of said first and second formation means includes recess means into which said protruding means extend.

5. A circuit breaker as set forth in claim 4 in which the extension is generally U-shaped including spaced arms connected by a base, said handle being seated on said base, said second formation means including portions on each of said arms.

6. A circuit breaker as set forth in claim 4 in which the extension is generally U-shaped including spaced arms connected by a base, said handle being seated on said base, said second formation means including portions on each of said arms and formed integral therewith.

7. A circuit breaker as set forth in claim 1 in which the extension is generally U-shaped including spaced arms connected by a base, said handle being seated on said base, said second formation means including protrusions on said arms extending outboard therefrom, said first formation means including spaced recesses in said handle into which said protrusions extend.

8. A circuit breaker as set forth in claim 7 in which the extension is constructed of metal and the protrusions are integral sections of said arms. 

1. A circuit breaker including a housing having an openable cover, cooperating contact means disposed within said housing, an operating mechanism disposed within said housing and connected to said contact means for opening and closing the later, a molded insulating handle extending through an opening in said cover, a handle extension disposed within said housing in operative engagement with said operating mechanism, first formation means on said handle and second formation means on said extension, said first and second formation means being snap-fitted to each other for securement of said handle to a portion of said extension disposed within said housing whereby said cover may be opened even while said handle is positively held to said extension.
 2. A circuit breaker as set forth in claim 1 in which the first formation means includes spaced recesses and the second formation means includes spaced protrusions that extend into said recesses.
 3. A circuit breaker as set forth in claim 2 in which the protrusions are disposed at opposite sides of the extension and extend outboard of said sides.
 4. A circuit breaker as set forth in claim 1 in which one of said first and second formation means includes protruding means and the other of said first and second formation means includes recess means into which said protruding means extend.
 5. A circuit breaker as set forth in claim 4 in which the extension is generally U-shaped including spaced arms connected by a base, said handle being seated on said base, said second formation means including portions on each of said arms.
 6. A circuit breaker as set forth in claim 4 in which the extension is generally U-shaped including spaced arms connected by a base, said handle being seated on said base, said second formation means including portions on each of said arms and formed integral therewith.
 7. A circuit breaker as set forth in claim 1 in which the extension is generally U-shaped including spaced arms connected by a base, said handle being seated on said base, said second formation means including protrusions on said arms extending outboard therefrom, said first formation means including spaced recesses in said handle into which said protrusions extend.
 8. A circuit breaker as set forth in claim 7 in which the extension is constructed of metal and the protrusions are integral sections of said arms. 